There are two kinds of fools: one who says this is old and therefore good, and the other who says this is new and therefore better. The argument between the two is as old as humanity itself, but technology's relentless exponential advance has made the divide deeper and more contentious than ever. My greatest fear is that this divide will frustrate the sensible application of technological innovation in the service of solving humankind's greatest challenges.

The two camps forming this divide need a name, and "Druids" and "Engineers" will do. Druids argue that we must slow down and reverse the damage and disruption wrought by two centuries of industrialization. "Engineers" advocate the opposite: we can overcome our current problems only with the heroic application of technological innovation. Druids argue for a return to the past, Engineers urge us to flee into the future.

The Druid-Engineer divide can be seen in virtually every domain touched by technology. Druids urge a ban on GMOs, while Engineers impatiently argue for the creation of synthetic organisms. Environmental Druids seek what the late David Brower called "Earth National Park," while Engineers would take a page from Douglas Adam's planet-designing Magratheans in Hitchhikers Guide to the Galaxy, making better Earth by fixing all the broken bits. Transhumanists and singularitans are Engineers; the Animal Liberation Front and Ted Kaczynski are Druids. In politics, Libertarians are Engineers, while the Greens are Druids. Among religions, Christian fundamentalists are Druids and Scientologists are Engineers.

The gulf between Druid and Engineer makes C. P. Snow's Two Cultures seem like a mere crack in the sidewalk. The two camps do not merely hold different worldviews; they barely speak the same language. A recent attempt to sequester oceanic carbon by dumping iron dust in the Pacific off of British Columbia intrigued Engineers, but alarmed Druids who considered it an act of intentional pollution. Faced with uncertainty or crisis, engineers instinctively hit the gas; Druids prefer the brake.

The pervasiveness of the Druid-Engineer divide and the stubborn passions demonstrated by both sides reminds me of that old warrior-poet Archilochus and his hedgehog-fox distinction revived and elaborated upon by Isaiah Berlin. Experience conditions us towards being Engineers or Druids just as it turns us into hedgehogs or foxes. Engineers tend to be technologists steeped in physics and engineering. Druids are informed by anthropology, biology and the earth sciences. Engineers are optimists—anything can be fixed given enough brainpower, effort and money. Druids are pessimists—no matter how grand the construct, everything eventually rusts, decays and erodes to dust.

Perhaps the inclination is even deeper. Some years back, the five year-old daughter of a venture capitalist friend announced upon encountering an unfamiliar entree at the family table, "It's new and I don't like it." A Druid in the making, that became her motto all through primary school, and for all I know, it still is today.

We live in a time when the loneliest place in any debate is the middle, and the argument over technology's role in our future is no exception. The relentless onslaught of novelties technological and otherwise is tilting individuals and institutions alike towards becoming Engineers or Druids. It is a pressure we must resist, for to be either a Druid or an Engineer is to be a fool. Druids can't revive the past, and Engineers cannot build technologies that do not carry hidden trouble.

The solution is to claw our way back to the middle and a good place to start is by noting one's own Druid/Engineer inclinations. Unexamined inclinations amount to dangerous bias, but once known, the same inclination can become the basis for powerful intuition. What is your instinctive reaction to something new; is your default anticipation or rejection? Consider autonomous highway vehicles: Druids fear that robot cars are unsafe; Engineers wonder why humans are allowed to drive at all.

My worry is that collective minds change as a snail's pace while technology races along an exponential curve. I fear we will not rediscover the middle ground in time to save us from our myriad folly. My inner Engineer is certain a new planetary meme will arrive and bring everyone to their senses, but my gloomy Druid tells me that we will be lucky to muddle our way through without killing ourselves off or ushering in another dark age. I will be happy if both are a little right—and a little wrong.